Deillim machine



(No Model.) F. VOOS.

DRILLING MAGHINE. No. 273,409. Pa'tented Ma,.r.6,1883.

N. PEIERS. Fhnla-Ulhngnpller, Washin ton. D. B.

UNITED STATES PATENT OFFICE.

FBANZ VOOS, OF S OLINGEN, PRUSSIA, GERMANY.

DRlLLlNG-MACH|NE.

SPECIFICATION forming part of Letters Patent No. 273,409, dated March-6,1883.

V Application filed June 5, 1882. (No model.)

To all whom it may concern:

Be it known that I, FRANZ V008, of Solingen, in the Kingdom of Prussia,in the Einpire of Germany, have invented a new and useful Protector forDrills, of which the following is a specification.

A great objection to the use of twist or spiral drills is the dangeroftheir breaking, generally close to the drill-head. To prevent this isthe nature of my invention, which consists in inclosing the twist-drillin a suitable casing, out of which only the end of the drill projects,and so arranged that the drill can easily move downward, according tothe depth of the hole.

In the accompanying drawings, Figure I represents the drill, with easingattached to the drill-head in section. Fig. II is an end view of thesame. Fig. III is a side view of the case and drill. different views ofdrill and easing referred to in the following specification.

Similar letters represent similar parts in all the figures.

A represents a twist or spiral drill; B, the case surrounding the same;G, the end of the drill-head; D D, thejaws in the drill-head forsecuring the drill and case, acted upon by the screws E E.

The case B must be made to correspond exactly with the size of thedrill, so that the latter can freely pass through the same. It isadvisable, and I prefer, to cut the case B open on one side, as shown at(1, Figs. II and III, so that when fastened between the jaws D in thedrill-head O the case will grip the drill firmly. At the lower end ofthe case B projections n n are made at the inside, fitting into thegrooves or spiral recesses of the drill,

and whereby the motion received by the case B from the drill-head willbe communicated to the drill. The end of the case B may be Figs. IV, V,and VI showmade with projections m m at its lower end, to

bear upon the work to be drilled, (see Figs. V and VI,) open oppositethe projections n n, to allow the free escape of the drill-chips.

The drill A is moved downward by means of a screw, J, Fig. IV, passingthrough the end of the case B and bearing against the end of the drill.

The case B may likewise be surrounded by another case, H, provided witha key or feather, 14;, working in a corresponding groove, u, in the caseB, Fig. V, in which case the case H is fastened between the jaws D D inthe drill-head, the feather w, working in the groove 1;, communicatingthe motion to the case B, and the feeding-screw J passing in that casethrough the end of this outer casing, H.

Instead of the feeding screw J and the feather it working in the groove11, the drill A may be fitted into the end of the case H by means of asquare head, at, Fig. VI, whereby the motion given to the case H isdirectly communicated to the drill A, the inner case, B, being in thatcase provided with a collar, 8, through which, by means of any suitabletool, the case B can be moved downward or .upward. It will be perceivedthat by the arrangement of this case B the spiral drill A will beprotected and strengthened throughout its whole length, leaving only theend to penetrate the material free and liable to break.

What I claim as my invention, and desire to secure by Letters Patent, is

In combination with a twist or spiral drill, A, the case B, providedwith projections n n, fitting into the spiral grooves of the drill,arranged to operate in the manner and for the purpose substantially asdescribed.

FRANZ VOOS.

Witnessesn' HANS FRIEDRICH, G. A. LANGENINSSEN.

